This is how you get things done. Stef Alexander, aka P.O.S., recently visited SPIN's NYC office and decided to make up a new song on the spot.

"I'm gonna make a super simple beat," the Minneapolis-based rapper told the assembled crowd of staffers, "and then I'm gonna read a verse that I just finished writing for you all, SPIN." And sure enough, he cobbled together a sampled groove on a beat box, pulled out his cellphone (where he typed up his lyrics), and dropped a rhyme for a never-before-heard jam.

We've invited dozens of performers to join us for stripped down performances over the years, but since "unplugged" doesn't exactly translate to hip-hop, only a few brave souls have attempted to make it happen. P.O.S. has risen to the challenge -- twice. Watch his most recent performance above! (Via SPIN)